The relationship of lung function with ambient temperature

<div><p>Background</p><p>Lung function is complex trait with both genetic and environmental factors contributing to variation. It is unknown how geographic factors such as climate affect population respiratory health.</p><p>Objective</p><p>To determine whether ambient air temperature is associated with lung function (FEV₁) in the general population.</p><p>Design/Setting</p><p>Associations between spirometry data from two National Health and Nutrition Examination Survey (NHANES) periods representative of the U.S. non-institutionalized population and mean annual ambient temperature were assessed using survey-weighted multivariate regression.</p><p>Participants/Measurements</p><p>The NHANES III (1988–94) cohort included 14,088 individuals (55.6% female) and the NHANES 2007–12 cohort included 14,036 individuals (52.3% female), with mean ages of 37.4±23.4 and 34.4±21.8 years old and FEV₁ percent predicted values of 99.8±15.8% and 99.2±14.5%, respectively.</p><p>Results</p><p>After adjustment for confounders, warmer ambient temperatures were associated with lower lung function in both cohorts (NHANES III <i>p</i> = 0.020; NHANES 2007–2012 <i>p</i> = 0.014). The effect was similar in both cohorts with a 0.71% and 0.59% predicted FEV₁ decrease for every 10°F increase in mean temperature in the NHANES III and NHANES 2007–2012 cohorts, respectively. This corresponds to ~2 percent predicted difference in FEV₁ between the warmest and coldest regions in the continental United States.</p><p>Conclusions</p><p>In the general U.S. population, residing in regions with warmer ambient air temperatures was associated with lower lung function with an effect size similar to that of traffic pollution. Rising temperatures associated with climate change could have effects on pulmonary function in the general population.</p></div

Adjusted survey weighted multivariate regressions to assess the effect of spirometry temperature in the NHANES III cohort^*.

<p>Adjusted survey weighted multivariate regressions to assess the effect of spirometry temperature in the NHANES III cohort^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0191409#t004fn001" target="_blank">*</a>}.</p

Survey weighted univariate regressions.

<p>Survey weighted univariate regressions.</p

Survey weighted means (± S.E.) for study cohorts.

<p>Survey weighted means (± S.E.) for study cohorts.</p

Survey weighted multivariate regressions unadjusted and adjusted for potential confounders for study population.

<p>Survey weighted multivariate regressions unadjusted and adjusted for potential confounders for study population.</p

Mean [95% CI] changes in plasma Lp(a) from baseline by diet in all participants (Fig. 1a) and in blacks and whites (Fig. 1b) are shown.

<p>P-values for differences to baseline (Fig. 1a) and between races (Fig. 1b) are displayed. All interventions increased Lp(a). Between races, study diets increased Lp(a) in blacks more than in whites with significant differences after the Prot diet.</p

Participant Characteristics at baseline¹.

1<p>HOMA, homeostasis model assessment; LDL-C, LDL cholesterol; HDL-C, HDL cholesterol; Apo, apolipoprotein. P values were derived from Student's t test comparing the different races. Values are unadjusted means ± SD.</p><p>Participant Characteristics at baseline^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114859#nt101" target="_blank">1</a>}.</p

Lp(a) concentration (mg/dl) with diet by ethnicity: Changes from baseline and differences between diets reported as mean [95% CI].

<p>Lp(a) concentration (mg/dl) with diet by ethnicity: Changes from baseline and differences between diets reported as mean [95% CI].</p

Baseline Intake and Nutrient Targets of Omni Heart Diets.

<p>Baseline Intake and Nutrient Targets of Omni Heart Diets.</p

A pilot feeding study for adults with asthma: The healthy eating better breathing trial

<div><p>Rationale</p><p>Evidence from observational studies and to a lesser extent clinical trials suggest that a healthy diet may improve symptoms and lung function in patients with asthma. We conducted a pilot study to determine the feasibility of conducting a larger scale dietary trial and to provide preliminary evidence on the impact of a healthy diet on asthma outcomes.</p><p>Methods</p><p>In a randomized, two period cross-over trial, participants with asthma received a 4-week dietary intervention followed by a usual diet (or vice versa), separated by a 4-week washout. The dietary intervention was a healthy diet rich in unsaturated fat. During the dietary intervention, participants ate three meals per week on site at the Johns Hopkins ProHealth Research Center. All remaining meals and snacks were provided for participants to consume off-site. During the control diet, participants were instructed to continue their usual dietary intake. Relevant biomarkers and asthma clinical outcomes were assessed at 0, 2, and 4 weeks after starting each arm of the study.</p><p>Results</p><p>Eleven participants were randomized, and seven completed the full study protocol. Among these seven participants, average age was 42 years, six were female, and six were African American. Participant self-report of dietary intake revealed significant increases in fruit, vegetable, and omega-3 fatty acid intake with the dietary intervention compared to usual diet. Serum carotenoids (eg. lutein and beta-cryptoxanthin) increased in the intervention versus control. Total cholesterol decreased in the intervention versus control diet. There was no consistent effect on asthma outcomes.</p><p>Conclusions</p><p>The findings suggest that a feeding trial in participants with asthma is feasible. Larger trials are needed to definitively assess the potential benefits of dietary interventions on pulmonary symptoms and function in patients with asthma.</p></div